Focus groups are typically 6-8 people, strangers, who meet to discuss a particular brand. Focus groups aim to have some commonality in terms of the invited people - e.g. they might share consumer spending habits, they might all be customers of a particular brand, product, service or organisation or they might share psychographics. What do we mean by that? Let's suppose you wanted to understand people who bought hi-fi equipment, some people are prepared to pay a huge amount for hi-fi equipment so you could run a session which looks at these 'enthusiasts'. So when do you use depth interviews, why wouldn't you just run focus groups?

Depth interviews are useful as a stand-alone or a compliment to focus groups. A depth interview is typically an hour to an hour and a half. Depth interviews are useful if the subject matter is very personal, for example - you might be talking about health issues or finance which people typically might not want to discuss in a group. Furthermore, focus groups have a tendency to find group 'norms' so they might say they buy stereo every 2 years because that's what everyone else has said when, in fact, it might be they only buy it every 3 years. So depth interviews tend to be more accurate but there's a downside.

Depth interviews are more expensive and take longer because you do them one at a time. Furthermore, if you are looking to understand perceptions of a brand, you do group exercises such as coming up with words or images associated with a brand, now in a group environment people spark off each other so you get great depth in terms of understanding. By contrast if you are one on one with someone doing an exercise such as what words do you associate with a brand you won't get that richness.

So to summarise, depth interviews are useful when the subject matter is private or where you want to understand detailed decision making. Depth interviews are also useful for business subjects and themes. Focus groups are better for understanding the detailed perceptions of a brand, service, product or organisation. More often than not you are best place to do a balance of both.

About the author

Jake Pearce

"Different to get better results". Jake is obsessed with marketing ROI. He helps companies amplify word of mouth to get business more easily. He uses Meanomathics to boost Comms cut through 10-30%. He uses co-creation to future proof innovation - he turned around a drinks category providing 15% growth using professional co-creation. And he helps top CEO and celebrities with their personal branding and brand purpose, which links back to Word of Mouth marketing.

Jake Pearce is a specialist in brand planning, development & innovation. Jake is currently working on a Word of Mouth Marketing start-up, a personal branding start-up and new delivery systems for wellness products.